Multiple-fuse plug



E. M. KING.

MULTlPLE FUSE PLUG. APPLICATION FILED APR. 22. 1.918.

1,336,238 Patented Apr. 6, 1920..

ELGIN M. KING, OIE NIAGARA FALLS, NEW YORK.

MULTIPLE-FUSE PLUG.

Specification of Letters Patent.

Patented Apr. 6, 1920.

Applicationflled April 22, 1918. Serial No. 229,973.

To all whom it may concern Be it known that I, ELGIN M. KING, a citizen of the United States, residing at Niagara Falls, in the county of Niagara and State of New York, have invented new a fresh or unblown fuse into service when another is blown, thus prolonging the life of the plug.

It is the object of my invention to improve such multiple fuse plugs with a view of simplifying their construction, reducing their cost of manufacture and insuring a reliable contact between the plug and the socket with which it cooperates.

In the accompanying drawings: Figure 1 is a "sectional elevation of a fuse plug embodyinlg the preferred form of the invention. igs. 2 and 3 are crosssections thereof on the correspondingly -numbered lines. Fig. 4 is a view of the front end of the plug.

Similar characters of reference indicate corresponding parts throughout the several views.

1 indicates the body of the plug preferably constructed of a single piece of porcelain or other suitable insulating material. Applied to the reduced front portion of the plug is the customary metallic screwring or threaded contact shell 2 adapted to engage the usual internally-threaded receiving-socket of the plug, not shown in the drawings.

Extending lengthwise of the plug and arranged substantially equidistant in a circular row are the fuses 3 of the plug. The

are preferably provided at their front en s with enlargements or contacts 4 countersunk in recesses 5 in the adjacent end of the plug. The other ends of the several fuses are soldered or otherwise electrically connected to a metallic disk or manifold 6 edge of the disk and extends laterally therefrom and thence forwardly through an opening 8 in the wall of the plug to the hub or contact-head 15.

shell 2 constitute the terminal contacts of usual contacts of the plug-socket.

shell. The enlarged rear portion of the plug is recessed to form a chamber 9 in which the adjacent portions of the several fuses are arranged. This chamber is divided by radial partitions 10 into as many compartments as there are fuses, each compartment containing a single fuse. These partitions may consist of mica or other appropriate refractory material which prevents the spark or heat from a blown fuse from reaching the adjacent intact fuses. These partitions may be suitably connected or interlocked at their inner edges while their outer edges are seated in longitudinal grooves 11 in the wall of the chamber 9. The open rear end of this chamber is closed by a head 12 of mica or similar material which is retained in position by a cap or flanged ring 13, through the central opening of which the several fuses are visible for inspection.

Cooperating with the circular row of fuseends or contacts 4. is a rotatable metallic switch-arm or member 14 connected to a This head and the the plug which are adapted to engage the switch arm is carried by a rotary spindle 16 arranged in an opening 17 formed axially in the reduced front portion of the plug body. The spindle is also capable of sliding lengthwise in said opening, so that the contact-finger 18 of the switch arm may be moved into and out of the sockets 5 of the plug as well as rotated on theplug to bring said finger into contact with the end of any one of the fuses for the purpose of successively or selectively throwing them into service as required. The spindle is yieldingly held in its normal retracted position by a spring 19 surrounding it and bearing at its front end against a shoulder of the plug-body and at its rear end against a head or collar 20 of the spindle.

A disk 21 of mica or other suitable material may be interposed between the front end of the plug and the hub 15 of the switch arm, this disk rotating with the arm and being provided with an aperture 22 for the passage of the finger 18.

In the use of the plug, the switch arm 14 is turned to engage one of the fuses, as shown by full lines in Fig. 1, and the plug is then screwed into the usual socket, thus completing the. circuit through the switch This arm, the active fuse, manifold disk 12, conductor 7, and the shell 2. Should said active fuse blow out, the plug is removed from lts socket and the switch arm 1s withdrawn to the dotted position shown in Fig. 1 and turned until its finger 18 comes opposite a fresh fuse, when the arm is released and the finger allowed to snap into contact with the intact fuse. The spring 19 of the spindle reliably holds the switch arm in engagement with the fuse.

Aside from the quickness and convenience with which an intact fuse can be switched into service when another is blown, the construction shown has the advantages of simplicity and cheapness, as the manifold 'conductor-disk 12 forms a single inexpensive connection between the several fuses and the shell 2.

It will be noted that the terminal contact formed by the hub or button 15 of the switch arm normally bears against the rigid inner end of the plug body and therefore forms a reliable contact with the complementary contact of the usual socket into which the plug is screwed.

The plugs shown in the drawings are provided with four fuses, but a greater or less number may obviously be employed.

I claim as my invention:

1. A multiple fuse-plug comprisin a bod of insulating material, a shell apfiied to t e front portion of said body, a plurality of fuses arranged in said body and having their front ends disposed in a circular row at the corresponding end of the body, a conducting disk arranged in the rear portion of said body and connecting the several fuses at their rear ends, a conductor permanently connecting said disk with said shell, a rotary spindle arranged lengthwise of said body and disconnectedfrom said disk, and a switch arm mounted on said spindle and arranged to selectively engage the front ends of the fuses.

2. A multiple fuse plug, comprising a body of insulating material having a threaded shell, a plurality of fuses arranged lengthwise in said body and disposed in a circular row at its front end, a conducting disk connecting the several fuses at their rear ends, a conductor extending laterally from said disk and thence lengthwise of the plug body to said shell, and a rotary switch arm mounted on the front end of the plug body and arranged to selectively engage the a jacent ends of the fuses.

ELGIN M. KING. 

